The first thing you notice on seeing The Strypes play is what a phenomenal live band they are, wailing and howling and strutting like a raw rhythm and blues band.

The second thing you notice is the crowd – recently, the band have been packing out rooms around the country, and with audiences flecked with rock royalty.

And the third thing you notice is their age. The Strypes are a proper phenomenon. Four boys aged 15 and 17, they are players with chops way beyond their years, the hard-earned result of years spent honing their craft in Irish pubs, hotels and music halls, where they’d often play for up to two and a half hours at a time. “The Irish pub band ethos is play for really long, or you’re no good,” says guitarist Josh. “And sometimes there’d be five people there, and they’d just want to hear play ‘Whiskey In The Jar’,” says drummer Evan. “So we developed a trick to make them pay attention – we play really LOUD!”

Bassist Pete O’Hanlon, drummer Evan Walsh and guitarist Josh McClorey have known each other as long as they can remember, growing up together in Cavan, a small, pleasant, working class town near the border with Northern Ireland. And for just as long, they’ve been delving into the record collections of their parents.

It’s in the black plastic grooves of their parents’ LPs that they became fans of a series of artists not commonly discussed among their peers: Doctor Feelgood and Dave Edmunds, Howlin’ Wolf and Bo Diddley, Muddy Waters and ‘Baby Face’ Leroy Foster. They can talk at great length – and frothy enthusiasm – about all of them. “We started off listening to Stiff Records and The Stones and the ‘60s bands, then it was listen to this, listen to this, and then it kind of went back to the '50s – and then the '40s, '30s and '20s…,” says Ross.

They’re not retro snobs – they like Jack White, The Black Keys, Arctic Monkeys, Jake Bugg, Miles Kane and more – but they do place themselves in direct opposition to the X Factor artists and manufactured pop. “The X Factor is not about people wanting to be an artist and share music, it’s just get rich quick, 15 minutes of fame,” says bassist Pete. “There’s no artist satisfaction – it’s just going through the motions of getting famous for a couple of months or years. It’s artificial.”

In falling in love with this music, they started doing what generations of blues lovers did before them – playing the music themselves, assembling into a crack guitar, bass and drums formation. Singer Ross Farrelly was the last to join, recruited after he appeared solo on the same bill as the band. He donned his trademark Ray Ban shades at his first group performance and the image stuck. “It started because I was nervous – I wore them so I wouldn't be able to see anybody,” he says. “Then it just became a thing – I become a completely different person on stage.”

The Strypes' days of gigging around Ireland in a converted disabled access van eventually got them noticed. They landed slots on The Late, Late Show, they started touring overseas and – thanks to their snappy dressing – they caught the attention of A&R from Elton John’s management company. “He first spotted us walking through a Tube station,” says Pete.

The three elder members of the band quit school after their Junior Certs last summer. Singer Ross is still theoretically a schoolboy, but the band’s whirlwind year has been a major distraction. As 2012 went on, things became increasingly surreal. Elton John personally called to talk about signing them. Squeeze songwriter Chris Difford signed on as a mentor. Towards the end of 2012, Noel Gallagher turned up to see them play, they met Jeff Beck and Paul Weller invited them to support him, later saying, "I saw that band The Strypes recently and it was just, 'Wow'. The guitarist is fucking amazing. Really raised my game that did."

The band have already met their musical heroes – and they aren’t phased by it at all. “Everyone’s really normal,” says Josh. “I think it’s the best part about them. It’s just like meeting anyone, but they’re just really lovely and genuine and they have HUGE talent.”

With most of them, the band have something in common – a deep love for the blues. It’s why the band play a hefty set of covers by artists little-known outside of those in the know. “They’re fantastic songs and it’s part of carrying on the blues tradition – not just covering songs but reinterpreting them and letting people hear them,” says Pete. “It feels like it’s a mission of sorts – not to educate because that sounds like a superiority thing – but to let people know there’s a lot of good music out there if you want to listen to it.”

Now signed to Mercury Records, The Strypes are setting about preparing their debut album, and writing new material to add to live favourites ‘Mystery Man’ and ‘Blue Collar Jane’. “The album will be a mix of covers and our own material,” says Evan. “And it’ll be loud.”

Despite their age, despite the whirlwind excitement surrounding them, the band are keeping their feet on the ground for now. “There's a lot of bullshit associated with the celebrity aspect of the music business, all the drink and drugs and the rest of it, but we're just more interested in being around music,” says Pete. “There's a bit of interest now we're signed and all but if that didn't happen we'd still be playing small gigs in Cavan,” says Josh. “We don't care if we're not famous – we just want to play rhythm and blues.”